Support for Partitions

Partitions are just another vault with individual config, but operations on vaults are
aware of partitions. This allows sharing of keys for example, and alters the way
vaults are displayed when showing them.

Features

• add partitions and remove them
• initialize new vaults with partitions in mind
• show recipients per partition

Improvements

• Allow sy vault to operate anywhere with a .gpg-id file, like pass.
• Strong validation of the vault configuration to assure consistency

Breaking Changes

• vault --vault-id is now vault --select